The arrival of Chinese President Hu Jintao to India was the first by a Chinese head of state for 10 years. They now describe their relationship as one of global importance.

Correspondents say Mr Hu's visit marks an improvement in relations between the two major economies, after decades of hostility and fierce competition for resources.

The Indian prime minister said that there was enough space for the two countries to develop together in a "mutually supportive manner" after talks with President Hu.

The two sides are expected to sign a 10-year agreement to increase investment and form a free trade area embracing two-point-four billion people or a third of mankind.

They will also sign a host of agreements on energy and economic cooperation. Both share a need for oil and energy and view each other with a mix of suspicion and self-interest.

Security was tight in Delhi as President Hu began his visit. Once the handshakes and formalities were dispensed with, the two sides got down to some hard talking.

While the talks began in earnest so too did demonstrations by Tibetan exiles based in India. China is unlikely to allow Indian firms to invest in politically-sensitive Tibet.

The Tibetan government-in-exile, led by the Dalai Lama, is hosted by India and is based in the country's north-west. There are around 120,000 Tibetan exiles in India.

Some Tibetan activists say they were barred by Delhi from attending the protests for fear of upsetting the Chinese president's sensitivities over the issue.

But the two leaders diplomatically ignored the Tibet question, as well as lingering border disputes and China's alleged role as the main weapons supplier to India's rival, Pakistan.